Clippless bicycle pedal

Abstract: A clipless bicycle pedal employing a clamping mechanism which engages a binding plate (70) on the bottom of a rider's shoe. The clamping mechanism includes two units (38, 40) which pivot about the same axis to engage the binding plate and which may share a biasing mechanism. The pivot axis maybe the same axis as the pedal shaft (12). The overall structure of the preferred embodiment provides a clipless pedal which is lightweight and easy to assembly and maintain.

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is directed to bicycle pedals and components. More particularly, the present invention is directed to bicycle pedals incorporating binding mechanisms which are used with binding plates on a shoe worn by a rider. 2. Background of the Invention In order to hold a rider's shoe in position on a bicycle pedal, bicycle pedals including toe-clips are employed to grasp the front portion of each of the rider's shoes. The toe-clips in conjunction with pedals and straps allow both downward and upward motion to be transmitted as drive force, however, toe-clips have the disadvantage that they do not provide for easy disengagement in the event of a fall. Thus, clipless pedals have been developed to overcome the disadvantages of pedals having toe-clips. Clipless bicycle pedals use a binding mechanism on the pedal to engage a plate on a rider's shoe to hold the shoe in position on the pedal. The binding mechanism prevents the shoe from slipping off the pedal, while also providing for easy disengagement when stopping or in the event of a fall. Clipless pedals may also provide a positive pedalling force during both the upward and downward motions of the pedal. Conventional clipless pedals generally include a pedal body having a binding mechanism mounted thereon to engage said plate. The pedal body is, in turn, rotatably mounted on a pedal shaft. The binding mechanism includes a retaining claw fixedly mounted to said pedal body and a movable claw movably mounted to said pedal body and a spring which urges the movable claw toward the plate fixed to the bottom of the rider's shoe. The binding mechanism and said plate are designed to cooperate with each other so that a horizontal twisting or sliding movement of said plate produces a movement of the movable claw, permitting disengagement of said plate. German Gebrauchmuster No. 93 00 261.0, which corresponds to the preamble of claim 1, discloses a bicycle pedal which enables the engagement and disengagement of a rider's shoe at two positions. A clamping means is provided at each of those positions, and comprises a threaded axle, a hooked plate arranged to rotate about that axle and a plate spring to bias the hooked plate to engage the rider's shoe. Due to the particular arrangement of the engaging and clamping means on the pedal body of these prior art pedals, engagement and/or disengagement of the rider's shoe can be sometimes difficult. SUMMARY OF THE INVENTION It is an object of the present invention to provide a clipless bicycle pedal which facilitates engagement and/or disengagement of the rider's shoe. Accordingly, the present invention comprises a bicycle pedal adapted for engagement and disengagement of a binding plate on a rider's shoe, said pedal comprising: binding plate engaging means for engaging said binding plate at at least one mounting position on the pedal, depending on the pedal orientation; binding plate clamping means spaced apart from and moveable relative to said engaging means and for engaging said binding plate at said position in combination with said engaging means; and biasing means for biasing said clamping means relative to said engaging means; characterized in that: said engaging means and said clamping means are both configured to rotate about a common axis while permitting relative rotational movement of said engaging means and said clamping means about said common axis. Because the engaging means and the clamping means rotate about a common axis while permitting relative rotational movement between them, then the problem of providing a pedal which facilitates engagement or disengagement is solved. In fact the rotational freedom or play provided by the arrangement allows a limited relative movement between the engaging and clamping means which facilitates engagement and/or disengagement of the plate under the rider's shoe. In a preferred embodiment, the biasing mechanism includes a single helical biasing spring which is axially mounted over the pedal shaft to operate the binding mechanism. An adjustment screw is provided which adjusts the tension of the biasing spring thereby adjusting the binding strength of the binding mechanism. In the preferred embodiment, the components of the binding mechanism include an inner mounting block having a cylindrical cavity, a central block having a cylindrical cavity and an outer mounting block having a cylindrical cavity. In addition, the binding mechanism includes first and second clamping members and corresponding first and second engaging members. The inner, central and outer mounting blocks are rotatably mounted to the pedal shaft which is received through the cylindrical cavities. The helical biasing spring is axially mounted over the shaft. One end of the helical biasing spring is coupled to the inner block while the other end is coupled to the central block. The first and second clamping members are attached to both the inner and outer mounting blocks so as to hold the inner and outer mounting blocks together, forming a plate clamping unit, and to move therewith about the longitudinal axis of the pedal shaft. The first and second engaging members are mounted to opposite sides of the central block, so as to form a plate engaging unit, which also rotates about the axis of the pedal shaft. The biasing spring biases the plate clamping unit and the plate engaging unit rotationally about the pedal shaft axis so as to provide a clamping action to engage the binding plate mounted on the bottom of the shoe. The binding plate engaging means may be further configured to move a relatively small amount in a direction parallel to the axis of the pedal shaft. Also the plate clamping means may be further configured to move a relatively small amount in a direction parallel to the axis of the pedal shaft. The present invention will be described now by way of example only with particular reference to the accompanying drawings. In the drawings, BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a bicycle employing a clipless pedal in accordance with the present invention; Figure 2a is a perspective view of a bicycle crank and pedal assembly of the bicycle of Figure 1 and Figure 2b is a partial cut-away view of the crank arm and pedal shaft showing an optional rotatable mounting of the pedal shaft; Figure 3 is an exploded view of a first embodiment of a clipless bicycle pedal constructed in accordance with the present invention; Figure 4 is a top view of the clipless bicycle pedal of Figure 3; Figure 5 is a top cut-away view of the clipless bicycle pedal of Figure 4 which shows the principal components in an assembled configuration; Figure 6 is an end cut-away view of the clipless bicycle pedal, showing the operation of the clipless bicycle pedal during engagement with a binding plate fixed to the sole of a rider's shoe; Figure 7 is another end cut-away view showing the operation of the spring bushing and tension adjustment screw; Figure 8 is another end cut-away view showing the position of the torsion spring; Figure 9 is another end cut-away view of the clipless bicycle pedal, showing the operation of the clipless bicycle pedal during engagement with a binding plate fixed to the sole of a rider's shoe; Figure 10 is another top view of the clipless bicycle pedal showing the engagement of the binding plate; Figure 11 shows a first embodiment of a binding plate for use with the clipless pedal of the present invention; Figure 12 shows a second embodiment of a binding plate for use with the clipless pedal of the present invention; Figure 13 shows an exploded view of a second embodiment of a clipless bicycle pedal for use with the binding plate of Figure 12; Figures 14 and 15 show end cut-away views of the second embodiment of the clipless bicycle pedal, showing the operation of the clipless bicycle pedal during engagement with the binding plate of Figure 12 at a first position; and Figures 16 and 17 show end cut-away views of the second embodiment of the clipless bicycle pedal, showing the operation of the clipless bicycle pedal during engagement with the binding plate of Figure 12 at a second position with the pedal rotated 90 degrees. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Figure 1 is a perspective view of a bicycle 80 employing a clipless pedal in accordance with the present invention. The bicycle 80 includes the familiar elements of front and rear wheels 82 and 84, frame assembly 86, seat 88, handlebars 90, fork 112, rear sprocket 114 and chain 116. In addition, bicycle 80 includes clipless pedals 10(a)-10(b) attached to left and right crank arms 102 and 104 respectively. Mounted to a shaft (not shown) which connects the left and right crank arms 102 and 104 on the right side of bicycle 80 is at least one sprocket 110 onto which chain 116 is mounted for driving the rear sprocket 114. Additional elements, including derailleurs for multiple sprockets and brakes may be added to bicycle 80 if required. In Figure 2a, a more detailed perspective view of crank arm 102 and clipless pedal 10(a) is shown. In a first embodiment, clipless pedal 10(a) includes a binding mechanism 11 rotatably mounted on pedal shaft 12. Binding mechanism 11 is adapted to engage a binding plate on a rider's shoe, as discussed in more detail below, to firmly hold the shoe without use of a conventional toe clip and strap. The binding mechanism 11 also serves as the pedal body making a very lightweight pedal having the advantage of clipless binding. The binding mechanism 11 preferably includes a binding plate engaging unit and a binding plate clamping unit which are biased relative to each other by a biasing means. As used herein the term "bias" or "biasing" when used with respect to two elements, means providing a tendency for the two elements to move relative to each other. Such movement may be rotational, linear or a combination thereof. In Figure 2b, an embodiment with a spindle 12 rotatably mounted to crank arm 102 is illustrated. This rotatable mounting is provided through a bearing assembly 13 configured within crank arm 102. This allows some parts of binding mechanism 11 to be fixedly mounted to pedal shaft 12 if desired. Bearing assembly 13 may be a ball bearing assembly or may employ other well known bearing types. Referring now to Figure 3, an exploded view of an embodiment of a clipless bicycle pedal 10(a) constructed in accordance with the present invention is shown. The binding mechanism 11 includes an inner mounting block 14, an inner bushing 54, a spring bushing 22, a helical biasing spring 20, a biasing spring adjustment screw 32, a central mounting block 18, a central bearing means 56, an outer mounting block 16, and outer bushing 26 and a retaining nut 24. Mounted on the top and bottom of central mounting block 18 are first and second engaging members 42 and 44, while mounted to both inner mounting block 14 and outer mounting block 16 are first and second clamping members 38 and 40. Central mounting block 18 and first and second engaging members 42, 44 cooperate to form a plate engaging unit. Inner mounting block 14, outer mounting block 16, and first and second clamping members 38, 40 cooperate to form a plate clamping unit. It should be appreciated that the specific pieces cooperating to form the binding mechanism illustrated in Figure 3 are only exemplary and may be varied in both number and configuration. For example, while the plate engaging unit is illustrated configured as three pieces, i.e. engaging members 42, 44 and central mounting block 10, it may also be one integral piece. Equally, two or more portions may be used for the mounting block 18 similarly to the two piece clamping unit mounting block approach as illustrated by pieces 14, 16. Also, although an annular opening in the mounting blocks to accept pedal shaft 12 along an axis of the opening is illustrated, a non-annular opening may be employed. For example, the opening may be defined by two or more semi-circular portions. Furthermore, the manner of coupling the various pieces illustrated in Figure 3, and/or their material of composition may be varied. For example one of the portions of the plate engaging unit may be mounted rotatably about pedal shaft 12. Additionally, all or a portion of the plate engaging unit may be made of elastic material to provide some play or movement within the unit so as to facilitate engagement and/or disengagement or to alter the "feel" of the binding to the rider. Also, a portion of the plate engaging unit may be pivotally mounted to the other portion(s) of the unit to allow limited movement during engagement and/or disengagement. The pivot axis of such pivoting portion may be perpendicular or parallel to the pedal shaft axis. Alternatively, telescopic movement between at least one portion of the engaging unit and the other portion(s) of the unit may be provided. Similarly, while the plate clamping unit is illustrated configured as several separate pieces, it may be formed as one integral piece, or two or more portions, may be used. Similarly, a single mounting block may be employed as in the case of the plate engaging unit as illustrated in Figure 3. Although annular openings in mounting blocks 14, 16 are illustrated, non-annular openings may be employed. One of the portions of the plate clamping unit may be mounted rotatably about pedal shaft 12 and at least one of the other portions may be mounted relative thereto. Additionally, all or a portion of the plate clamping unit may be made of elastic material. Optionally, one of plate clamping unit or plate engaging unit may be wholly or partially made of elastic material with the other being rigid, so as to provide a desired degree of play or movement during engagement and/or disengagement. Also, a portion of the plate clamping unit may be pivotally mounted relative to other portion(s) thereof to allow limited movement during engagement and/or disengagement to facilitate such engagement and/or disengagement. The pivot axis of such portion may be perpendicular or parallel to the pedal shaft axis. Alternatively, a relative telescopic movement between at least one portion of the clamping unit and the other portion(s) of the unit may be provided. Continuing with the embodiment illustrated in Figure 3, pedal shaft 12 is preferably made of a single portion of alloy steel of sufficient strength for the desired application and has one or more cylindrical portions each having a diameter corresponding to, but slightly smaller than, the bore of each of inner bushing 54, spring bushing 22 and central bearing means 56. In forming the binding mechanism 11, inner bushing 54 may be press-fitted into inner mounting block 14. Similarly, central bearing means 56, which may be a plain bearing, a needle bearing, a ball bearing, or a combination of such bearings, is press fitted into central mounting block 18. Inner mounting block 14 is rotatably mounted on a first cylindrical portion of pedal shaft 12 via inner bushing 54 while spring bushing 22 is rotatably held within an annular shaped cavity of inner mounting block 14 and over a second cylindrical portion of pedal shaft 12. Similarly, central mounting block 18 is rotatably mounted to a third cylindrical portion of pedal shaft 12 via the central bearing means 56. Retaining nut 24 engages a threaded portion of pedal shaft 12 to retain central mounting block 18, spring bushing 22 and inner mounting block 14 on pedal shaft 12. The retaining nut 24 may be replaced with other retaining means, such as a snap ring or washer and bolt. Thus, the plate engaging unit and the plate clamping unit, comprised respectively of inner mounting block 14, outer mounting block 16, and central mounting block 18, each are allowed to rotate about the axis of the pedal shaft 12 independently of each other. A number of alternate mounting approaches may equally be employed while providing the desired rotational freedom. For example, pedal shaft 12 may be made of two or more cooperating portions in which one portion is fixedly attached to crank arm 102, and the other cooperating portion(s) are rotatably mounted to the first portion. One of the plate engaging unit or plate clamping unit may then be directly mounted to the rotating portions. Alternatively, one of the plate engaging unit or plate clamping unit may be integrally formed with a rotating portion of the pedal shaft. Alternatively, one portion of the plate engaging unit or plate clamping unit may be rotatably mounted to a portion of the other unit. The other unit is then mounted to the pedal shaft 12 in a fixed manner for a rotatable pedal shaft portion, or is rotatably mounted onto or into a pedal shaft portion which is itself fixedly attached to the bicycle crank arm. The axis of rotation of the plate clamping unit or plate engaging unit rotatably mounted to the other unit may or may not share the same longitudinal axis as the pedal shaft. Furthermore, at least two binding positions in an angular direction about such axis of rotation of the rotatably mounted unit may be provided. Additionally, the manner in which the mounting of the various portions provides rotational freedom may be varied in numerous ways by employing well known bearing types and combinations. For example, bearing means 56 may be press-fitted into each of inner mounting block 14 and outer mounting block 16, while central mounting block 18 may contain a press-fitted bushing which acts as a plain bearing. A needle bearing may also be employed at one or more of these positions on the plate engaging unit or other bearing types may be employed. The plate clamping unit may similarly contain any of the above described types of bearings, or other well known bearings, so that either of plate engaging unit or plate clamping unit may be mounted via a variety of bearing types to pedal shaft 12. Additionally, either of plate engaging unit or plate clamping unit may contain a cylindrical portion which serves as a rotatable mounting for the other unit, and the unit not containing the cylindrical portion may be mounted about the axes of pedal shaft 12 and the cylindrical portion. Finally, either or both of plate engaging unit or plate clamping unit may be rotatably mounted at one or both ends to pedal shaft 12, or to both pedal shaft 12 and a portion of the other unit. One or both of the units may be mounted in such a way that permits play in a direction parallel to the axis of the pedal shaft 12 either with respect to the pedal shaft or with respect to the other unit. This arrangement allows a binding plate engaged to the unit to also have some play. Continuing with Figure 3, central mounting block 18 includes a cylindrical portion upon which outer bushing 26 is rotatably mounted. Outer mounting block 16 is then slidably fitted over outer bushing 26, and is held in place by screws 34 and 36 which thread into first and second clamping members 38 and 40. First and second clamping members 38 and 40 are also attached to inner mounting block 14 by screws 28 and 30. Thus, inner mounting block 14, outer mounting block 16 and first and second clamping members 38 and 40 are fixed together and are able to rotate around the axis of the pedal shaft 12 as a single clamping unit. Spring bushing 22 is held within a cylindrical cavity of inner mounting block 14. Spring bushing 22 has spring engaging slots 17, 19 and 21 which receive one end of biasing spring 20. One of the three slots 17, 19, 21 may be selected during assembly for a rough setting of the biasing spring force. The other end of biasing spring 20 engages opening 58 in central mounting block 18. A plurality of openings for receiving one end of biasing spring 20 may be provided in central mounting block 18 also for a rough setting of the biasing spring force. Biasing spring 20 is thus mounted between spring bushing 22 and central mounting block 18. Spring bushing 22 includes a flattened portion which interacts with a biasing spring adjustment screw 32 for adjusting the rotational force (i.e. torque) required to rotate said plate engaging unit about the axis of the pedal shaft 12 with respect to said plate clamping unit. Biasing spring 20 provides the force needed to engage the binding mechanism to a binding plate fixed to the bottom of the rider's shoe as discussed below. Biasing spring 20 also provides the force which may be needed, depending upon the overall configuration, to keep the binding plate engaged to the binding mechanism. A seal (not shown) to exclude moisture and dirt and/or to retain lubricants within the binding mechanism may be included at possible entry points to the binding mechanism, for example, between pedal shaft 12 and the plate engaging unit or plate clamping unit. A seal may also be provided on either or both of the plate engaging unit and plate clamping unit to retain lubricant and/or exclude dirt and water from these units individually. Alternatively, the seal may be configured between the plate engaging unit and plate clamping unit and at the inner and outer ends of the binding mechanism. The seal between the clamping and engaging unit may be configured to connect the plate engaging unit and plate clamping unit yet allowing independent rotation of each unit around the pedal shaft axis. It will be appreciated that any combination of these sealing arrangements which assures adequate containment of lubricant and/or exclusion of moisture and dirt may be employed. Lubricant injection openings (not shown) may also be employed in inner mounting block 14, outer mounting block 16, and/or central mounting block 18. One or more gates may be provided for allowing injected lubricant, such as grease, to purge out from the gates to remove dust and other particles trapped between the lubricant injection openings and the gates. One or more routes may also be provided to allow the lubricant to pass between the plate engaging unit and plate clamping unit. The routes may also be closable so as to force lubricant only into the plate engaging unit or plate clamping unit to which the lubricant opening is provided. By selectively closing the routes between the units or the gates on some portions of the units, the routes may be combined to allow control of the lubricant to provide penetration through either unit or to force lubricant out through the gates, thereby ensuring lubricant penetration to desired locations within the pedal. In Figure 4 a top view of the clipless bicycle pedal 10 is shown. As shown in Figure 4, engaging member 42 is mounted to central mounting block 18 by screws 46 and 48, while clamping member 38 is fixedly mounted to inner mounting block 14 and outer mounting block 16. This arrangement allows engaging member 42 to rotationally move relative to clamping member 38 about the axis of pedal shaft 12 during engagement and disengagement of the binding plate. Referring to Figure 5, the engagement of biasing spring 20 with respect to spring bushing 22 and central mounting block 18 is shown. As shown in Figure 5, one end of biasing spring 20 is inserted into one of slots 17, 19, 21 (21 being shown) and, with respect to the rotational position of inner mounting block 14, is fixedly held by the combination of spring bushing 22 and adjustment screw 32. The other end of biasing spring 20 is inserted into an opening 58 in mounting block 18. The arrangement allows the clamping unit and engaging unit to rotate in relation to each other about the axis of the pedal shaft 12 under spring tension. Stated differently, the engaging unit is allowed to rotate in either direction from a neutral position which is determined by the position of adjustment screw 32. In addition, biasing spring adjustment screw 32 may be replaced by an adjustment plate or a mechanically-operated dial. It should be noted that this biasing force adjustment means is not mandatory in completing the binding mechanism. For example, spring bushing 22 and adjustment screw 32 may be dispensed with and a hole in inner mounting block 14 may be provided for receiving one end of biasing spring 20 to securely position the spring 20 with respect to other components of the binding mechanism. In another embodiment, an alternate biasing mechanism may be used in place of the helical spring. For example, an elastic material other than metal may be used in place of the helical spring, in either a compression or expansion configuration, to provide a relative biasing force between the plate engaging unit and the plate clamping unit. Alternatively, a portion of the engaging unit or clamping unit may be made of elastic material which is attached to or abuts against the other unit in a compression or expansion mode to provide the biasing force. Further, the biasing mechanism may be mounted outwardly on either the engaging or clamping member rather than being concealed within the binding mechanism. Such outwardly mounted biasing means may provide a biasing force either directly from one unit to the other or indirectly via a shoe, i.e., the biasing force acts from one unit to a shoe and reacts upon the other unit. Alternatively, the biasing mechanism may be provided on the rider's shoe rather than being configured within the binding mechanism. For example, the biasing mechanism may be an elastic material or spring mounted outwardly on the bottom of the rider's shoe, so as to bias the units toward each other when the rider steps into the binding mechanism. Continuing with Figure 5, portions 60-a and 60-c integrated with inner mounting block 14 and Portions 60-b and 60-d integrated with outer mounting block 18 touch against stoppers 62-a, 62-c, 62-b and 62-d integrated with first and second engaging member 42 and 44 respectively. This arrangement keeps the biasing force which otherwise rotates the clamping unit, looking from crank arm 102, clockwise with respect to central mounting block 18, from making such rotation beyond the stoppers. Thus, whenever the clamping unit is pushed, again looking from crank arm 102, counter-clockwise, a biasing force, countering to the force pushing the clamping unit, always exists. In another embodiment, clipless pedal 10 may have additional binding positions for engaging the binding plate. For example, clipless pedal 10 may have outer and inner binding positions which provide different locations for binding along the central axis of the pedal shaft or along an axis parallel to the axis of the shaft. For example, in the former case the binding mechanism 11 illustrated in Figure 2 may be duplicated at a position inward toward crank arm 102 along pedal shaft 12 or outward along the direction of the axis of shaft 12. The clipless pedal of the present invention may also be combined with a conventional pedal platform, either employing a conventional toe clip or not, to allow convenient use with or without a specially adapted shoe. Such conventional pedal platform may be provided at any of various positions relative to the clipless pedal portion of the combined pedal. For example, the conventional and clipless pedal positions may be side-by-side in the direction of the pedal shaft, side-by-side but offset relative to the pedal shaft, or spaced apart in the length direction of the bicycle. Similarly, the clipless pedal of the present invention may also be combined with other types of plate binding mechanisms. For example, a movable claw and another biasing means may be mounted onto the outer mounting 16 to form an additional binding mechanism in conjunction with one of clamping member 38 or 40. The operation of clipless pedal 10 in the preferred embodiment will now be discussed with reference to Figures 6 and 9. As shown in Figure 6, a binding plate 70 is fixed to the sole of each of the rider's shoes for engaging to engaging hook 43 and clamping hook 39. To engage, the front of the binding plate 70 is first hooked into the engaging hook 43. The rider then pushes down on the rear of the shoe, as shown in Figure 9, causing the engaging unit 42 and clamping member 38 to rotate about the axis of pedal shaft 12. The angled surface 72 of binding plate 70 forces the distance between engaging hook 43 and clamping hook 39 to increase. A chamfered surface 74 on clamping hook 39 then allows the clamping unit, rotated by the biasing force, to return to its original position providing secure engagement of binding plate 70 between engaging hook 43 and clamping hook 39. Binding plate 70 can then be released from the engagement between engaging hook 43 and clamping hook 39 by rotating binding plate 70 in horizontal direction about an axis behind engaging hook 43 in a manner which disengages the plate clamping unit first. Clipless pedal 10 may also have additional engaging and disengaging modes in which the functions of plate engaging unit and plate clamping unit are different from that described above. For example, the shape and configuration of the binding plate and engaging and clamping hooks may require that the binding plate be first engaged to plate clamping unit prior to engaging the plate engaging unit. Also, while disengagement occurs first at the rear of the binding plate, i.e. from the plate clamping unit in the illustrated embodiment of Figure 6, it may equally be designed to disengage the front of the plate first. In still another engaging and disengaging mode, the designed function of the plate engaging unit and plate clamping unit may be substantially similar, so that either of the plate engaging unit or plate clamping unit may be engaged or disengaged in any order as desired by the rider. Further, whereas engagement has been described above as a vertical downward motion and disengagement as a horizontal movement, either engagement or disengagement may be equally achieved by movement of the binding plate in a direction substantially vertical or horizontal to the pedal shaft 12 in an appropriate design. Thus, any combination of vertical and horizontal movement for engagement and disengagement may be employed. Figure 7 shows one embodiment of spring bushing 22 which provides plural slots 17, 19 and 21 for attaching biasing spring 20. Depending the particular hole selected, the basic tension, i.e. biasing force, of the spring can be selected, with finer tension adjustments being made by the tension adjustment screw 32. As shown in Figure 8 pedal shaft 12 is inserted actually through biasing spring 20, so that the resulting biasing forces act circumferentially about the pedal shaft 12. Since the diameter of biasing spring 20 will change as torsional forces are applied, ample room is provided within the cylindrical portion of innermounting block 14 to accommodate this change. This configuration thus provides a simply and easily maintained biasing system. Figure 10 is a top view of the clipless bicycle pedal showing the engagement of the binding plate. As shown in Figure 10 the front portion of the binding plate is engaged under portion 43 of engaging member 42 and the rear portion of the binding plate is clamped under portion 39 of clamping member 38. Figure 11 shows one embodiment of the binding plate for use with the clipless pedal of the present invention. The binding plate shown in Figure 11 includes the front portion and rear portions shown in Figures 9 and 10. Figure 12 is another embodiment of a binding plate for use with the clipless pedal of the present invention. The binding plate of Figure 12 is designed to allow the plate to be engaged to the clipless pedal at one of two distinctly different modes, as will be discussed in connection with Figures 14 through 17. Figure 13 is an exploded view of a second embodiment of a clipless bicycle pedal for use with the binding plate of Figure 12. The major components of the second embodiment shown in Figure 13 correspond generally to that of Figure 3 and will not be described again in detail. Also, like numerals to Figure 3 will be employed. The illustrated components include an inner mounting block 14 an inner bushing 54, a spring bushing 22, a helical biasing spring 20, a biasing spring adjustment screw 32, a central mounting block 18, a central bearing means 56, an outer mounting block 16, an outer bushing 26 and a retaining nut 24. Also included are first and second engaging members 42, 44 and first and second clamping members 38, 40. The specific dimensions and configuration of the illustrated components is altered from the embodiment of Figure 3 to allow the binding plate to be attached in either of two modes at respective positions of the pedal rotated through 90 degrees as shown in Figures 14 through 17. Referring to Figures 14 and 15, the operation of the clipless binding pedal during engagement with the binding plate of Figure 12 in the first binding mode is shown. As shown in Figure 14, the middle front portion 92 of the binding plate is hooked under the engaging hook 43 of the engaging unit while the middle rear portion 94 of the binding plate is hooked beneath the clamping hook 39 of the clamping unit. The biasing force provided by the biasing spring forces these two hook portions together. Thus, as shown in Figure 15, the binding plate is engaged between the engaging hook 43 and the clamping hook 39 in a manner similar to the embodiment of Figure 3. Referring to Figures 16 and 17, the engaging mode at a position rotated 90 degrees counterclockwise from that of Figures 14 and 15 is illustrated. The outer front portion 96 of the binding plate now is hooked over the outside of the clamping hook 39 while the outer rear portion 98 of the binding plate is hooked over the outside of the engaging hook 45. In this configuration, the biasing force acts to separate the clamping hook 39 and engaging hook 45. The binding plate is thus engaged outside of both the clamping hook 39 and the engaging hook 45 as shown in Figure 17. Note that the difference between Figures 14 and 15 and Figures 16 and 17 is that in Figures 14 and 15, the binding plate is between the engaging member and the clamping member while in Figures 16 and 17, the binding clamp is outside of the engaging member and the clamping member. Note also that Figures 14 through 17 show the same clipless pedal and binding plate, the difference being that the clipless pedal is rotated 90° so that there are four separate binding positions available on this embodiment of the clipless pedal. The foregoing description of the present invention is of a preferred embodiment which is subject to a number of modifications without departing from the scope of the invention. Accordingly, the foregoing description of the preferred embodiment should only be viewed as illustrative and limited only by the following claims.

Claims: A bicycle pedal (10a,10b) adapted for engagement and disengagement of a binding plate (70) on a rider's shoe, said pedal comprising: binding plate engaging means (42,44) for engaging said binding plate (70) at at least one mounting position on the pedal, depending on the pedal orientation,; binding plate clamping means (38 or 40) spaced apart from and moveable relative to said engaging means (42 or 44) and for engaging said binding plate (70) at said position in combination with said engaging means; and biasing means (20) for biasing said clamping means relative to said engaging means; characterized in that: said engaging means (42,44) and said clamping means (38,40) are both configured to rotate about a common axis while permitting relative rotational movement of said engaging means and said clamping means about said common axis. A bicycle pedal (10a,10b) according to claim 1 wherein said engagement occurs at one of two or more positions which are angularly spaced about said common axis. A bicycle pedal (10a,10b) according to claim 2 wherein: said binding plate engaging means comprises first (42) and second (44) binding plate engaging members coupled to move together; and said binding plate clamping means comprises first (38) and second (40) binding plate clamping members coupled to move together. A bicycle pedal (10a,10b) according to claim 3 wherein: said first (42) and second (44) binding plate engaging members are disposed on opposite sides of said common axis; and said first (38) and second (40) binding plate clamping members are disposed on opposite sides of said common axis. A bicycle pedal (10a,10b) according to any preceding claim wherein said pedal is adapted for rotatable mounting to a pedal shaft (12) and both said engaging means (42,44) and said clamping means (38,40) are rotatably mounted to said shaft (12), said shaft thereby providing said common axis. A bicycle pedal (10a,10b) according to claim 5, wherein said biasing means comprises a helical spring (20) configured so as to receive the pedal shaft (12) therethrough. A bicycle pedal (10a,10b) according to claim 5, wherein said pedal shaft (12) is dimensioned to provide mounting surfaces for the components of said pedal. A bicycle pedal as set out in claims 1 or 2 wherein said binding plate clamping means further comprises an inner mounting block (14) and an outer mounting block (16) each attached to said plate clamping member (38,40) and rotatably mounted to a pedal shaft (12). A bicycle pedal (10a,10b) as set out in claims 1 or 2 wherein said binding plate engaging means further comprises a central mounting block (18) attached to said plate engaging member (42,44) and rotatably mounted to a pedal shaft (12). A bicycle pedal (10a,10b) as set out in claims 1, 2 or 6, wherein said biasing means comprises a helical spring (20) coupled to said binding plate clamping means (38) and to said binding plate engaging means. A bicycle pedal (10a,10b) according to claim 4 further comprising: a first pedal portion (18,42,44) having plate engaging members (42,44) integral therewith; and a second pedal portion (14,16,22,24,26,38,40) having plate clamping members (38,40) integral therewith. A bicycle pedal according to any preceding claim further comprising means (32) for adjusting the tension on said biasing means (20). A bicycle pedal according to any preceding claim wherein at least a portion (43) of said binding plate engaging means (42) and at least a portion (39) of said binding plate clamping means (38) engage said binding plate (70) therebetween, wherein said engagement occurs when a distance between said portion (43) of the binding plate engaging means (42) and said portion (39) of the binding plate clamping means 38 decreases and disengagement occurs when that distance increases. A bicycle pedal according to any one of claims 1 to 12 wherein at least a portion (45) of said binding plate engaging means (44) and at least a portion (41) of said binding plate clamping means (40) are engaged between at least two portions (96,98) of said binding plate (70), said engagement occurs when a distance between said portion (45) of the binding plate engaging means (44) and said portion of the binding plate clamping means (40) increases and disengagement occurs when that distance decreases. A bicycle pedal (10a,10b) according to claim 2 in combination with a binding plate wherein: said binding plate (70) has a middle front portion (92), a middle rear portion (94), an outer front portion (96) and an outer rear portion (98); said binding plate engaging means comprises first (43) and second (45) engaging portions; said binding plate clamping means comprises a clamping member (39); whereby, in a first mode, corresponding to one of said angularly spaced positions, said middle front portion (92) engages with said first engaging portion (43) and said middle rear portion (94) engages with said clamping portion (39); said engagement occurring when the distance between said first engaging member (43) and said clamping member (39) decreases; and whereby, in a second mode, corresponding to another of said angularly spaced positions, said outer front portion (96) engages with said clamping portion (39) and said outer rear portion (98) engages with said second engaging portion (45), said engagement occurring when the distance between said clamping member (39) and said second engaging member (45) increases. A pedal assembly comprising: a pedal shaft (12); and a pedal (10a,10b) according to any preceding claim. A crank arm assembly comprising: a pedal assembly (10a,10b,12) according to claim 16; and a crank arm (102) rotatably supporting said pedal assembly (10a,10b,12).

Inventors: MARUI SHINJI, MARUI, SHINJI
Applicants: MARUI SHINJI, MARUI, SHINJI
Application year: 1994
Main classification: B62M3
IPC codes: B62M3